Write the expression as a polynomial, using the corresponding formula for special product: (−y+x)(x+y), (−a+b)(b–a),(−b–c)(b–c),(x+y)(−x–y) ,(x–y)(y–x),(−a–b)(−a–b)

< coa = 150 ( given)

as ba and bc are tangents

so oc and oa is perpendicular to cb and ab respectively because in circle normal passes through centre

so in quadrilateral oabc

< coa + < oab + < ocb + < abc = 360

150 +90+90 + < abc = 360

330 + < abc = 360

< abc = 360 -330 = 30

so < abc = 30

⭐dhruv⭐

the correct option is b

step-by-step explanation: